The (jiialily of iMjttnm Ims however, imich to do witli (ho 

 -ciienil j'iid,^ ol' thi; FornniiiiiU'ni, :i.s witli other aniiii.ils. For, 

 ...^ shown nhove. eahu w;;lcr, widi a boUoiu oomiio.scd oi' lino sand 

 and .scdiiueiit, is particularly iavorahlo to tins arenaceous forms, 

 1houL,di, (>\vu uiuL'r tlRve conditions, they do nut thrive in the 

 very cold, deep water ( such as that below KM) lathonis) in the 

 open (III!!'. A strong- current at once causes all saudy forms to 

 tiisa[)pear, uio:-tly, uo doubt, trom want of the line materials 

 necessary ilu' their sliells, and brings in a ]arii,'o preponderance: o 

 Trnneatulinas, Lagenidie, &c. 



The arenaceous ibrms, with th(; exception of tr.o.-c which are 

 tubular, const itute a m ries parallel to the calcareous forms, and 

 the mendjcrs of which graduate into one another. It seems nnt 

 improbable that the individuals of tho same species may assunn; 

 cither appearance. It does nut appear, liowever, that the same 

 individual can present both ibrms at successive periods. On the 

 I'lher hand, the samly ibrms may really constitute a distinct 

 iirouj> paralkd to llu' others, irketches of some interesting forms ' 

 arepiven which do not appear to )jo precisely similar to descri))cd 

 species. TJicse liavc been kindly examined by ])r. i'arkcr, oi" 

 J.ondon, who re-ards the Lituoho represented in iigs. 1 and ?> a.s 

 new species, to whicli lie as.'^igns the names />. /iitdms and L. 

 (■■i:<st's. The Ibriu represented in ii-'. 2 lie regards as the type of 

 a lU'w K'-'ii"-, to which, from the horse-shoe .•shaped form of the 

 aperture, lie gives tho name J !ipp'>cr( ])!/(■', naming the species 



'J'.Vi;i,i; i.—,Siq>p-'Liniii'<irj/ Li.-:.' nf Pinilntr Anu'icrinis lornis. 



(Soc ri:-;s. I to 4, ,iiul I'lg, 7,) 



'ORAMINIIKRA. 



I.iliKil.i liiuloMsc, I'arkcr— Fiv, i 

 lli|)|)ocrL'pina indivisa, P.— i-i-. 

 l.itihila cassis, I'.T—Ki,;;. 3. ..... 



l.itiuila scoriniini'i — Fi-. .^ 



Var. — I'ii;. 4 



Rliabiloplfiira — I'ig. 7 



^ »' '-. V--, '- V- »-' 'ii CI r-. 



.15 *^- 1; "f^^ i~ 



>rii« I ^^ ~U* lA Z vT*- "/- 



^ -J 2 o 



«r r. * 

 •ci, 'c i 



*c' i 



*c I. * ; 



'CL....! 



cc 





